


all our secrets will one day end us

by bubblylikesparklingcider



Series: she is the slayer [1]
Category: Supernatural
Genre: M/M, There is an OFC, also metatron is a god from the hell dimension, because i couldn't really make claire the vampire slayer, she is the vampire slayer, vampire slayer, yes he's glory
Language: English
Status: Completed
Published: 2016-03-30
Updated: 2016-03-30
Packaged: 2018-05-30 05:17:19
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,846
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6410353
Author URL: https://archiveofourown.org/users/bubblylikesparklingcider/pseuds/bubblylikesparklingcider
Summary: <blockquote class="userstuff">
              <p>It starts on a Saturday morning. The story of how Dean and Castiel got married and ended up adopting a Vampire Slayer.</p>
            </blockquote>





	all our secrets will one day end us

**Author's Note:**

> Hello, lovely readers! I deleted my SPN/BTVS crossover because I didn't like it but then I thought that I'd write a story where Dean and Cas got married and adopted a Vampire Slayer. I was going to make it Buffy, but then I figured that would be weird, so it's going to be an OFC named Tessa instead. I hope you enjoy!

It starts on a Saturday morning, the first Saturday of Claire and Tessa's summer vacation. Castiel wakes up early, goes downstairs to start breakfast. The morning sun filters through the windows and illuminates the glass tiles in the kitchen. Cas hums as he cracks eggs into a skillet, stirs them around to scramble them.

"Morning, angel." Dean's voice is a low rumble in his ear as his husband wraps his arms around Cas' waist. 

"Morning, human." Cas responds and Dean chuckles. 

They met six years ago at a diner in Alabama, where the milkshakes were cold and sweet and perfect. Dean was a demon hunter, chasing after all things unholy, and Cas was a philosophy student that didn't want to have anything to do with his ultra-religious family. They'd clicked, gone back to a motel room together and the rest...well, the rest was history.

Dean left the hunter life behind two years later to settle down with Cas and Cas' daughter Claire in a little two bedroom house in Lawrence, Kansas, Dean's old hometown. Cas had gotten a job working at a nearby college and Dean began work as a mechanic. Both of them did surprisingly well at their jobs, and the owner of the garage, Bobby, eventually passed the garage on to Dean.

They moved houses and adopted Tessa two years ago, on Sam's recommendation. 

Bringing Cas back to the present.

"Can you go wake the girls?" He asks Dean, who nods and head upstairs.

"Claire, it's time to get up." Dean says upstairs. Cas listens as his husband heads down the hallway to Tessa's room. "Tess, come on, you gotta wake- Tessa?"

Cas freezes. That doesn't sound good. Claire stumbles into the kitchen, her hair a mess, and plops down at the table. 

"Cas, where's Tessa?" Dean says in a panicky voice as he comes back into the kitchen.

"I have no idea. She's not upstairs?" Cas asks, setting the skillet and the cooked eggs on the side.

"No. Claire, do you know where Tessa is?" Dean asks. The blonde teenager shakes her head sleepily.

"No clue. I think she might've snuck out last night, though." Claire yawns. "Can I have a chocolate bagel?"

"Of course, of course." Cas says absent-mindedly, pushing the bag of bagels towards Claire and mentally running through a list of all the places Tessa could be. At that moment, the back door swings open and Tessa steps into the kitchen, wearing a band tank top and skinny jeans. 

"Tessa Winchester-Novak, where the hell have you been?" Dean asks angrily. Tessa doesn't respond, just stares at him emptily. "Tessa, answer me."

Tessa still doesn't respond and Cas feels a pang of fear. She was fine yesterday, happy even. All smiles and laughs and sunshine. 

"Alright." Dean says, nodding. "If you won't tell me then I'll just assume you were at a party. You're grounded. Hand over your phone."

Tessa wordlessly hands Dean her phone. Even Claire's beginning to look at her weirdly now, because it's so very...un-Tessa. Cas would give anything for her to be screaming and storming upstairs right now.

Dean seems to realize something's wrong, because he relaxes slightly.

"Tessa, is everything okay?" Cas asks and Tessa seems to snap back for a moment.

"Everything's fine. I'm sorry I came back so late. I'm just gonna...go upstairs now." Tessa slips past Dean and heads upstairs. Dean and Cas stand staring at each other, a cold fear hanging in the room. As Dean reaches across the counter and takes Cas' hand, Cas wonders exactly what they're going to do now.

/----/----/----/----/

Everything runs smoothly for two weeks, something that scares Cas. Tessa is still practically mute, only speaking when she has to, constantly staring off into space with a mixture of fear and pain in her eyes. She looks almost dead, she hardly eats. Cas wants to take her to a doctor, but he doesn't want to give Tessa more of a reason to clam up on them.

The only bright side is that Gabe and Sam offered Tessa a job at their voodoo, hippie magic store that Tessa accepted without any urging. She gets out every day, and so Cas chooses not to push it.

Gabe and Sam come over a lot for dinner now, too, Sam constantly watching Tessa carefully, a concerned look in his eyes. Cas knows, he knows that Gabe and Sam know exactly what's wrong and they just won't say.

That's why it doesn't surprise him when he stumbles on Gabe and Sam having a private conversation in the living room.

"Dean and Cas are worried about Tessa." Gabe says and it's the most serious Cas has ever heard his brother. Everything is silent for a few moments.

"I know." Sam says finally. "But this...it's just so complicated, Gabe. This isn't a lesson that I can teach her. She's dealing with everything and I try to help her but she shuts me out. She needs...she just needs time."

"I know, baby. But maybe you need to urge Tessa to talk to her dads." Gabe says.

"I've tried that. Over and over and over again. In the back room of the magic shop, over lunch, even while she's researching something. She doesn't want to do it." Sam says and Cas decides he's heard enough and walks into the living room.

"Hey, dinner's ready." He says awkwardly and Sam and Gabe nod, stand up in tandem.

Dinner's a strange affair, and Cas is certain that Dean picks up on it. For once, Tessa's smiling and he's happy until Claire mentions something that sends the whole evening spiraling downward.

"Is ketchup just tomato blood?" Claire asks as she pushes a fry through a puddle of the condiment. 

"No, that would be tomato juice." Dean responds. "And what kind of question is that, anyway?"

"It's just the same color as regular blood. And it reminded me of this big bloodstain that I saw beneath the bank building yesterday." Claire says and Tessa freezes, the smile sliding off her face. Sam looks concerned all of a sudden. Even Gabe sets down his burger and Cas doesn't miss how he reaches under the table to hold Tessa's hand.

"What bloodstain?" Dean asks cautiously and Cas knows that he noticed.

"It's just this bloodstain! You know how tall that building is. It's 33 stories high. Do you think someone jumped?" Claire asks and Tessa stands up.

"Excuse me for a moment." She says quietly and heads off towards the bathroom. Sam and Gabe exchange a look and Cas feels worry take over.

Tessa doesn't rejoin them.

/----/----/----/----/

"What the hell is wrong with my daughter?!" Dean yells at Sam that night in the kitchen. Sam looks down at his hands, looking smaller than his 6'4" height.

"That's not for me to say, Dean." Sam says quietly and Dean bristles.

"I'm her father. I have a right to know." Dean snaps.

"Dean, this is for Tessa to tell you." Sam responds, looking up at his big brother.

"I don't care!" Dean yells and Sam stands up, slamming a fist down on the counter.

"It's not for me to tell you, Dean! Tessa has to tell you when she's ready." Sam yells back and Dean turns away, rubs at his forehead.

"I think you should leave." Dean says quietly and Sam nods. "I wish you'd tell me."

"I know." Sam says, heading for the door with Gabe. "But it really is Tessa's job."

/----/----/----/----/

The next morning, Dean and Cas insist on walking Tessa to the magic shop. (Well, Cas insists. Dean just goes along to please him.)

When they open the door, Gabe stands behind the counter, leafing through a book.

"Good morning, Tessa. Sam's in the back. We got a new book on vampires if you want to check it out before we open." Gabe says and Tessa nods and heads for the back room. Sam comes out a few moments later, wiping dust off his hands.

"Dean." He says and Dean nods, arms crossed over his chest.

"Dean, come on." Cas whispers gently and Dean sighs, lets his arms fall.

"I'm sorry I yelled at you, Sammy." Dean says.

"And I'm sorry that I can't tell you what's wrong with Tessa." Sam responds quietly. 

"I know why you can't." Dean says. "I don't like it. She's my daughter. But I get it. And I guess...I guess I can wait until she's ready."

"Or you could sit her down and ask her." Sam says gently. Dean nods again.

"I could." He says. Tessa peeks her head around the corner then.

"Uncle Sam, is that a god hammer?" She asks eagerly. Sam smiles at her.

"Yes, it is. You, me and Gabe will try to lift it later." Sam says and Tessa disappears around the corner again.

"That's the happiest she's been all summer." Dean says and Sam shrugs.

"She likes it here. It's why we offered her the job. We figured she could spend more time here and get paid for it. She is a teenager, after all, and I'm sure she enjoys having extra cash." Sam says.

"Thank you." Cas says and Sam nods.

"I have to get to the garage, but I'm sorry again, Sammy." Dean says and Sam hugs him.

"S'fine, D." He responds. "Now go! I know how much you like tinkering with cars."

As they leave, Cas wonders if maybe Tessa would like a ride to and from the shop. It's worth it, he thinks, if he can see her smile.

/----/----/----/----/

Cas goes back later that day to pick Tessa up. When he pushes open the door, he nearly has a heart attack.

The god hammer.

He's seen it in books before. It takes the strength of a god to pick it up.

Tessa's carrying it. By herself. In one hand.

"Papa!" She exclaims, setting it down guiltily.

"Um, hi Cas. We weren't expecting you to be back." Sam says, scratching the back of his head awkwardly.

"I just came to pick Tessa up." Cas says, trying to remain calm. 

"Okay. Yeah. I can just- go get my stuff." Tessa says, scuttling towards the back. 

"Is that real?" Cas asks, trying to lift it. He can't. It's too heavy.

"Cas, remember: it's for Tessa to tell you." Sam says and Cas nods slowly, taking a deep breath.

"Right." Cas says just as Tessa rounds the corner.

"I'd offer for you to take the hammer...." Sam trails off.

"But now's not the time." Tessa finishes glumly. "I know."

"Let's get home." Cas says. "Dean's making chicken piccata tonight, and I think he wants to talk to you."

/----/----/----/----/

"I don't want to push, Tess." Dean begins as they sit down in the living room. Tessa is nervously twisting a solid gray band around her finger. Cas notices that it's inscribed with runes.

"Okay." Tessa says quietly.

"We care about you. You haven't been acting the same all summer. Is there anything you want to tell us?" Dean asks.

"Maybe start with the hammer." Cas suggests. The room is silent until Tessa looks up, tears resting in her blue eyes.

"Uncle Sam...." She trails off, looks down at her hands again. "Uncle Sam thinks it's PTSD. I can't- I guess he's right. I still have nightmares. I keep having panic attacks. I always think he's behind me, ready to just-" She breaks off with a sob.

"Shh, Tessa, it's okay. Who's 'he'?" Dean asks.

"Metatron." Tessa says and Dean sucks in a breath beside Cas.

"As in the god from the hell dimension?" Dean asks and Tessa nods. "Okay. Okay. What were you doing around Metatron?"

"I don't know how to tell you!" Tessa exclaims. "I didn't want you to have to find out this way!"

"Tessa, it's okay." Cas says, sitting beside her. "It's fine. We're your parents and we love you and you can tell us anything."

"Have you ever heard of a Vampire Slayer?" Tessa asks and Dean shrugs, but Cas is certain that he knows. "It's like- okay. The Slayer is the one chosen to protect the world from evil. Vampires. Demons. Mainly vampires."

"Oh, god." Dean says, buries his face in his hands. "You're- you're the Slayer, aren't you?"

"Yeah." Tessa says quietly. 

"Tessa, that's- do you know how dangerous that is?" Dean asks.

"Of course I know, Dad. I'm the one that comes face to face with vampires every night." Tessa says and Dean groans.

"Metatron." Cas reminds them quietly and Tessa nods.

"Metatron. God from the hell dimension. He wanted to- I don't know. Something about melding worlds in some weird Norse thing, I didn't understand. I wasn't really listening. But anyway." Tessa takes a deep breath. "The bloodstain at the bottom of the bank building. It's my blood."

Cas feels faint. Dean grips his hand tightly and nods at Tessa to go on.

"We were fighting on the roof. And I- I wasn't- god. I wasn't paying attention." Tessa's sobbing now and Dean pulls her into a hug. "I had my back turned and he- he just snapped my neck. And- pushed me- off the top. And then five minutes later, I woke up in an alleyway because Uncle Gabe used a resurrection spell to bring me back."

Dean rubs her back soothingly, her head tucked underneath his chin. "Okay."

"And then I went after him." She says, her voice clearing up. "And I killed him. I ended his sorry life and his sorry existence and his sorry plans but I can't forget what he did to me."

"Of course you can't." Cas says, brushing her hair out of her face. "Were you able to pick up the hammer because you're the Slayer?"

"Yeah." Tessa sniffles, sitting up. "I needed it when I killed Metatron. It would've been useful. Maybe I wouldn't have died."

"Tessa, Metatron is a god. You couldn't- you wouldn't have been able to defeat him that easily." Dean says gently. "I'm surprised that you were able to kill him at all."

"Uncle Gabe has this knife and I just stabbed him in the face and he died." Tessa explains, rubbing at her eyes. Cas hands her a tissue.

"How do Gabe and Sam know about this and not us?" Dean questions and Tessa twists the tissue in her hands.

"Uncle Sam is my Watcher. It's why he urged you to adopt me. He figured it would be easier to train me if he was my uncle." Tessa says. "He taught me everything I know, he even went on my first patrol with me."

"Do you go on patrol every night?" Dean asks and Tessa nods. "Do you want to keep doing that?"

"Yes." Tessa says immediately. "I'm the Slayer, Dad. I have to do this."

"We need to set some ground rules, then." Dean says. "Firstly, you will let us know what's going on. Even if it's just some harmless little vampire, you tell us about it. We need to know."

"That's fair." Tessa nods.

"Secondly, you will NOT kill vampires in the house." Dean says and Tessa actually giggles.

"Dad, you have to invite a vampire in." Tessa says and Dean rolls his eyes.

"The rule still stands. Thirdly, you'll let us help you. If you're fighting something like Metatron, you let us research with you. We clear?" 

"Crystal." Tessa promises. Dean hugs her again.

"We love you, okay? This doesn't change that." Cas says and Tessa nods.

"You can talk to us. If you're having nightmares or panic attacks, tell us. We can help you." Dean says, just as Claire bounds into the house with a smile. "And maybe you should tell Claire."

"Tell me what?" Claire asks, puzzled. Tessa stands up and leads her off to the side.

"Sis, remember last week when we were attacked by those three guys?"

/----/----/----/----/

Tessa comes home that night with a bleeding nose, a wooden stake clutched in her right hand. She collapses on the couch beside Dean with a groan.

"I hate vampire gangs so much." She says as Cas grabs a tissue and tilts her head back to stop the bleeding. "They're the literal worst. I mean, what do they even do?"

"You fought a vampire gang?" Dean asks, setting his book aside and Tessa nods as best as she can with Cas holding her head back.

"Killed all of 'em, but one managed to get me." She says and Dean shakes his head.

"I'm never gonna get used to this, am I?" He asks and Tessa laughs, a sound that Cas hasn't heard in what feels like ages.

"Just you wait, Dad. Vampire gangs are the least of your worries." She says and Dean groans.

"I almost wish I only had to worry about boys." Dean complains and Tessa shrugs.

"Sorry." 

"No you're not."

"No. I'm not."

And Cas just hopes that they never have to deal with Tessa dying, never have to bury her because she faced down something too big for her. 

Maybe he'll pull out his old prayerbook again.


End file.
